Page:Popular Science Monthly Volume 31.djvu/444

430 showing its head and the other one the end of its tail. They are probably intended to be seals. On the same side of the horn are three figures of identical form, the meaning of which is not clear, and a figure that may be a hemipterous insect. M. Gaudry has no doubt of the authenticity of this specimen, for he is assured by M. Paignon, who is a lawyer and publicist of repute, and interested in prehistoric studies, that it was found in his presence by his own workmen while digging out the bone-earth from the bottom of the cave.

"Educating up."—Dr. Andrew Wilson suggests that we might with advantage dismiss some of the less useful topics from the curriculum of the common schools, and supplant them by other topics of vital interest to every class of the community. Boys and girls, for instance, are frequently kept working at modern languages, drawing, classics, and other branches, when the teaching of physiology, health, and domestic economy would be of infinitely greater advantage to them in afterlife. Some people would think this to be educating down, but Dr. Wilson asks: "Is it certain that by limiting the 'extras'—or what are undoubtedly often useless topics in education in so far as the social life of many of the pupils is concerned—we should be educating down at all? In all likelihood we should rather be practicing the reverse procedure. By imparting a knowledge of the laws of health and economy, we should be enabling the teacher to discharge his duties in a fuller and truer sense than before. . . . Individual culture of such subjects lies at the root of all national advance in health and prosperity. As several writers have shown, the remedy for much of the misery and poverty now existent lies in the better use of the hours spent at school."

An Undulatory Theory of Odors.—M. P. Leclerc has propounded a theory that odor is, like light and sound, a phenomenon of undulation. He cites in support of his view that many substances, like sulphur and copper, do not emit odors until they are rubbed, and it is more reasonable to suppose that the rubbings cause undulations than that under that condition the substances emit matter which can not be detected except as a smell. Again, arsenious acid when thrown upon a burning coal, gives out thick gray fumes and an odor of garlic. In the solid state it has no smell, and no more in the vaporous state if no chemical change takes place in volatilizing it. But, when it is thrown upon the hot coal, a reduction takes place to arsenic, that is volatilized and then reoxidized on coming in contact with the air, and we have a smell accompanying the chemical action the same as in many other cases we have light or heat in connection with it. M. Leclerc, continuing his experiments with a rather imperfect instrument, claims to have produced interference of odors analogous with the interference phenomena of light.

Some British Weeds.—British farms and gardens are troubled by about a hundred and thirty species of weeds, annuals and perennials, with about a dozen biennials. Among the most troublesome and mischievous of them are the bind-weeds and the couch-grass, which will start to grow from so small a piece of root that it is almost impossible to get rid of them. The couch-grass is nearly in place in Italy, where the white, underground stems, which contain a considerable quantity of starch, are gathered and taken to market, to be sold as food for cattle and horses. A variety of this grass, called matt-grass, also finds a place in Holland, where it is put to use for binding together the sandy dunes and flats by the sea. Some weeds have a marvelous power of increase. The history of the ox-eye daisy in this country illustrates this property. Some seeds of the plant found their way in packages to the Island of Colonsay, in the west of Scotland; in the course of a few years the ox-eye had taken possession of the whole island. The common yellow toad-flax was introduced as a garden-flower by a Mr. Ranstead, and is known as the Ranstead weed. Chickweed is said to have been introduced as a bird-seed. The Scotch thistle arrived in a bed-tick filled with its down. The down, having been replaced with feathers, was thrown away, and soon found a congenial home. Some American plants, particularly the water-weed (Anacharsis alsinastrum), have